Noah Montena

Sensing RF Connector Tightness Using a Grounded Plate Capacitive Structure

This paper describes a grounded plate capacitive sensing technique for monitoring mated RF connector tightness. The capacitive sensing structure and conditioning electronics are fabricated on the surface of a small polystyrene disc which is integrated into the RF connector body. A model of the electrostatic-mechanical system accurately predicts the change in capacitance as a function of the torque applied to tighten the mated connectors. Mechanical displacement in the connector (or, indirectly, axial force on the mated connector) translates to a change in the period of an oscillator drive circuit. The sensing system is measured to provide a transducer sensitivity range from 0.15 pF/Nmiddotm at the initial connector mating force to 0.74 pF/Nmiddotm at the high end of mating force.

Experimental Verification of a Passive Sensing Node for Monitoring RF Connector-Coaxial Cable System Performance

The concept of a network of passive sensing node (PSN) devices for monitoring the integrity of radio frequency (RF) coaxial transmission lines and associated RF connectors in the UHF range of frequencies was introduced in a previous paper. This paper examines the performance characteristics of the subsystems of an individual PSN device. It provides experimental verification of S-parameters of the transmission line coupler model, which was described in the previous paper. Experimental verification is also provided for power monitoring, power harvesting, and backscatter telemetry subsystems. The PSN reports 8-bit precision data from each of its sensory inputs including connector tightness, relative humidity, temperature, propagating RF power, harvested voltage, and the system voltage reference. The communication protocol for this data exchange is also discussed. Based on the results of these experiments, it is shown that a PSN-based network for monitoring transmission systems should be feasible.